Sandwich grid



A. S. KNAPP SANDWICH GRID March 24, 1953 Filed March l0 1951 Uenzzor ndrew 5T A?? 0 @5mg M 94 @1M 71755.

Patented Mar. 24, 1953 SANDWICH GRID Andrew S. Knapp, St. Louis, Mo., assignor to Knapp-Monarch Company, St. Louis, Mo., a

corporation of Delaware Application March 10, 1951, Serial No. 214,897

6 Claims.

This invention relates to a sandwich toaster. and more particularly to sandwich toaster grids which may be connected with the grids of an ordinary wallie iron in order to convert it for use as a sandwich toaster. This particular application is directed to an improvement in the sandwich grids described in my patent on a Sandwich Toaster, No. 2,567,382, dated September 11, 1951.

In the sandwich toaster described in my above referred to patent, it was found that the time required to toast a sandwich was lowest when the vheat losses between the waffle grids and the sandwich grids was least. When the sandwich grids were rst utilized as substantially nat sheet metal attachments to the waie iron grid, the toasting time for a sandwich was approximately 7 minutes. When these substantially dat sheet metal grids were used, the sandwiches were often crushed -by the weight of the upper waflle iron grid. In the sandwich grid described in said patent, embossments were provided along a pair of opposite edges of the sandwich grid to cooperate with similar embossments in the oppositely facing sandwich grid to space the sandwich grids apart and to eliminate the crushing of the sandwich.

These embossments spaced a portion of the border of the sandwich grid further from the face of the waiile iron grid than the remainder of the sandwich grid and thus created a substantially large air pocket between the embossed portions of the sandwich grid and the face of the waie iron grid. The heat losses due to convection of air within the substantially large air pockets reduced the operating temperature of the sandwich grid and increased the toasting time for sandwiches. For example, the toasting time of the sandwich grid shown in said patent was approximately 10 minutes, and when the length of the embossments in the border of said sandwich grid was doubled, the toasting time for a sandwich increased to 13 minutes.

From the standpoint of sales appeal and efficiency in producing toasted sandwiches, it is desirable to provide a sandwich grid wherein the toasting time is as low as possible and yet to provide sandwich grids wherein the sandwiches will not be crushed. This can be accomplished only by reducing the heat losses between the waflle grid and the sandwich grid.

Furthermore, when there is -heat loss from the waiiie grid to the air seeping under the edges or border of the sandwich grid, the border of the sandwich grid tends to be cooler than thecentral portion of the sandwich grid and uneven-toasting of the sandwich may result. It is desirable that the temperature gradient of the sandwich grid from the central portion out to the border be as uniform as possible.

Thus, one of the objects of this invention is to provide a sandwich grid wherein the heat losses between the waille grid and the sandwich grid are reduced.

Another object of this invention is to provide a sandwich grid wherein the heat loss from the waffle grid, caused by convection of air under the border of the sandwich grid, is reduced.

A further object of this invention is to provide a sandwich grid wherein, by reducing the heat losses at the border, the temperature gradient over the toasting portion of the sandwich grid is maintained as uniform as possible.

Still another object of this invention is to provide a sandwich grid wherein the toasting time of the sandwich is considerably reduced.

With these and other objects in view, my invention consists in the construction, arrangement, and combina-tion of the various parts of my device whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, wherein:

Figure 1 is a top plan view of the sandwich grid;

Figure 2 is a cross section view of a pair of opposed sandwich grids mounted on waiile grids and is taken substantially on line 2-2 of Figure 1;

Figure 3 is a cross section similar to Figure 2 and is taken on line 3-3 of Figure 1;

Figure 4 is an enlarged detail view of a rib on the sandwich grid positioned in the overflow gutter of the wale grid.

Referring now to Figure 1 there is shown a sandwich grid generally designated by numeral Ii). This sandwich grid I0 may be made of sheet metal, or may lbe a casting, and comprises a central portion I2 and a border or edge portion I4.

Referring to the use of the sandwich grid ID with a waiiie iron grid, Figures 2 and 3 show a waffle iron grid I5 positioned in a casing member I 8. The waie grid I B includes a plurality of pyramids 20 having faces 2|, which, when viewed from above, give a grid-like appearance. The waile grid I5 also includes an edge portion 22 which lies in a plane parallel to and spaced from the faces 2I of the pyramids 20. These edge portions 22 engage each other when the waiile iron is being used to make wales, thus Spacing the faces 2| of opposite waffle grids from each other.

Adjacent the edge portions 22, and formed in' the waffle iron grid I6, is an overflow gutter 24 which runs continuously around the waffle iron grid. A portion of the waille iron grid IB between the overilow gutter 24 and the pyramids 2i) is designated at 26 and terminates in a plane spaced substantially midway between the faces 2| of the Waffle .irongrid pyramids 2D and the face of edge portion 22.

Referring back to the sandwich grid It, the central portion l2 is adapted to lie against or as close as possible to the faces 2| of the pyramids 20. The border or edge portion lli lies in a plane spaced from the plane of central portion I2 so as to provide clearance between the border lll and the portions 26 and 22 of the waiiie iron grid which are spaced from the plane of the pyramid faces 2l.

Formed in border I4 are a pair of embossments or bosses 28 which are adapted to engage similar bosses in an oppositelyfacing sandwich grid to space vthe sandwich grids apart as best shown inFigure 8. These-v bosses `28 include bearing strips 3i! which are spaced from the plane of the central Vportion i2 'of the sandwich grida distance equal to substantially half theY thickness of an ordinary sized sandwich.

Also embossed in border ifi are a pair of ribs 32 which areA adapted to extend into the overilow gutter 24 ofthe waiiieV iron grid upon which the sandwich grid is mounted. These ribs 32 extend in a direction generally opposite to the direction of the embossments 2t. The ribs 32 extend generally Vfrom adjacent one end of one einbossment 28 to the end of the next embossinent 23. The embossinents 32 extend over the entire portion of the border M except for that portion wherein embossrnents 28 are located.

The ribs 32 when positioned in the overlow gutter 2d cooperate with the bounding wall of the overlowvgutter 2t toy prevent movement of air in and out between the waffle grid and the sandwich grid. The air between the waffle grid i and the sandwich grid it) is substantially sealed therebetween and this reduces the heat losses at the edge of the sandwich grid. This maintains a more uniform heatcgradient vover the length of the sandwich grid, from the center of the sandwichl grid to the outer edges thereof, and thus providesy for more uniform toasting of the sandwiches.y This also serves to maintain the temperature oi the sandwich grid at the highest possible value.

These ribs 32v are adaptedto engage a portion of the wallie iron grid bounding lthe overflow gutter 24 so as to `provide a better seal against heat losses due to convection of air. As shown in Figure 4, the overflow gutter 2li is bounded by surface '34 which. has a-selected radius of curvature; and the ribs 32' have a radius of curvature smaller than the radius of curvature of the overow gutter. This provides that the ribs 32 will engage the wall :it ofthe gutter 51 in substantially a single line indicated at 35 along the length of the-rib and preferably at the innermost portion of the overflow gutter so that the central portion i2 of the .sandwich grid l0 'will be positioned as close as possible to the face 2i of the waiile iron grief;

Means sare A,also provided yfor removably attaching the sandwich grid to the waille iron grid, and such meansareshown as consisting of spring clips 36 riveted at 3% toa portion of the embossmentsg2f-,- Since most wallevirons ,are also provided with dividing ribs, which extend across theV face4 ofthe wafe, :iron grid and extend Y beyond the face plane 2i of the waffle iron grid, the back side of the central portion l2 of the sandwich grid l0 is provided with grooves di! coined in the back thereof to receive the extending tips of the dividing ribs so as to permit close contact between the central portion l2 and the face 2| oi the wallie iron grid.

The result of rthe use of ribs 32 on the sandwich grid Iil is that the toasting time of sandwiches is reduced to 5 minutes. The comparative results of the different forms of sandwich grids discussed herein showing the toasting time of sandwiches and the temperatures of the sandwichgrids is shownin the following tables of experimental results:

Table I Ribs in Bor- Sandwich Test No f; .der Extend- Toasting Bossed lng Into Over- Time (in ow (lutterl minutes) Table II Temperature Percent Ribs ln Borof Sandwich` Test No Bordel, der Extend- GridWhcn Bossed mg Into Over- Indicator flow Gutter Light Geesv Outl l cover by my claires any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

l. n combination with a waiile iron having ,Ka-

pair of opposed grids capable of having their opposed faces parallel when spaced apart, which waiile iron grids each includes an overflow gutter extending continuously around the edge thereof, a pair of similarly shaped sandwich grids each overlying a `wallie iron grid, each sandwich grid including a central portion, a border around said central portion overlying said overflow gutter in the wale iron-grid, portions of said border havingspaced embossments therein adapted to engage corresponding embossments in opposedsandwich'grids, so as to space apart the central portions of the opposed grids, the embossed portions of, said border beinga minor portion of the length of said border, and the remainder of said border having ribsformed therein extending into said overflow gutter.

2, A waiile iron andsandwich grid combination asset fort-h in claim l wherein vthe ribsin each|- sandwich grid n extend continuously along said border, between vsuccessive f embossrnents. f

3. In combination with a waffle iron having a pair of opposed grids capable of having their opposed faces parallel when spaced apart, which waflle iron grids each includes an overiiow gutter extending continuously around the edge thereof, a pair of similarly shaped sandwich grids each overlying a walle iron grid, each sandwich grid including a central portion, a border around said central portion overlying said overflow gutter in the wale iron grid, portions of said border having spaced embossments therein adapted to engage corresponding embossments in opposed sandwich grids, so as to space apart the central portions of the opposed grids, the embossed portions of said border being a minor portion of the length of said border, and the remainder of said border having ribs formed therein extending into said overiiow gutter engaging a portion of the wall of said overflow gutter.

4. A wale iron and sandwich grid combination as set forth in claim 1 wherein the ribs in said sandwich grid engage a portion of the wall of said overow gutter at substantially the innermost portion thereof.

5. A waiile iron and sandwich grid combination as set forth in claim 1 wherein the overow gutter in said Waille iron is formed with one radius of curvature, and wherein the ribs on the sandwich grids have a radius of curvature smaller REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,493,444 Burch May 6, 1924 1,804,196 Barnes May 5, 1931 1,839,112 Mills Dec. 29, 1931 1,900,619 Snyder Mar. '7, 1933 2,018,698 Allen Oct. 29, 1935 2,476,213 OConnor July l2, 1949 FOREIGN PATENTS Number Country Date 224,904 Great Britain June 11, 1925 

